Automatic packing machine for tobacco leaves

Abstract

An automatic tobacco baler is used for automatically knotting tobacco bales through hemp ropes, and is characterized by comprising a feeding mechanism, a knotting mechanism, a knotting mechanism, a knotting mechanism, a knotting mechanism and a knotting mechanism, and is characterized in that the feeding mechanism is used for receiving the tobacco bales to be knotted from upstream equipment; the conveying mechanism is used for conveying the cigarette packets to be knotted to a knotting position; the picking claw mechanism is provided with a plurality of sets of picking claws and is used for bundling and winding the hemp ropes on the tobacco bales; the knotting mechanism is provided with multiple sets of knotting devices corresponding to the multiple sets of picking claws and used for rotationally knotting hemp ropes bundled and wound on tobacco bales, and the tensioning mechanism is provided with multiple sets of tensioning devices with the number corresponding to the multiple sets of picking claws and the multiple sets of knotting devices and used for rotating and knotting the hemp ropes bundled and wound on the tobacco bales and tensioning the multiple sets of tensioning devices with the number corresponding to the number of the multiple sets of picking claws and the number of the multiple sets of knotting devices. The tensioning device is used for providing constant tensioning force for the hemp rope in the knotting process of the tobacco bale.

Description

Technical Field

[0001] The invention relates to the technical field of packaging, in particular to an automatic packaging machine for tobacco leaves. Background Art

[0002] In recent years, tobacco production in China has gradually adopted a specialized grading and purchasing model. Specifically, after initial grading by tobacco farmers, the leaves are provided to purchasers in the form of loose leaves, which are then packaged after specialized grading by the purchasers and provided to tobacco manufacturers in the form of cigarette packs.

[0003] The packaging of tobacco leaves is very necessary. This is because if the tobacco leaves are not packaged, the loose tobacco leaves will be fluffy after baking, with large gaps, and will be easily dried or damp, which will affect the quality of the tobacco leaves. In addition, the fluffy tobacco leaves are large in size, which is not conducive to storage and transportation. Currently, packaging is mainly done manually, and the tools are mostly simple tools made by tobacco farmers, such as wooden balers, which require a large number of workers, high physical labor intensity, high repetitiveness, and low efficiency.

[0004] On the other hand, manual packaging uses sacks and hemp ropes to pack and tighten. However, since the newly harvested tobacco leaves have a large expansion force when packaging, it is not only very physically demanding, but also difficult to ensure the uniformity of the shape and size of the tobacco packages.

[0005] At present, some automatic baling machines have been developed. However, although the existing mainstream technology has solved the problem of expansion and deformation of compressed bales, the knotting process still cannot be automated. This is because the existing knotting mechanism usually uses cotton rope, nylon rope, etc., which are smooth and easy to operate, while hemp rope must be used to tie cigarette bales. Hemp rope has the characteristics of high friction and low stretchability. Once the knot is completed, it is difficult to tighten it again.

[0006] Therefore, the knotting process of the current automatic tobacco baler still relies on manual stringing and manual knotting. Automatic tobacco baling cannot achieve higher automation like other automatic balers, which has become one of the factors restricting the implementation of professional tobacco grading and purchasing models. Summary of the invention

[0007] In order to solve the above-mentioned problems, the purpose of the present invention is to provide an automatic tobacco packing machine that can replace the previous manual knotting method to save labor costs and can form tobacco packs of uniform size and shape for easy storage and transportation.

[0008] In order to achieve the aforementioned objectives, an automatic tobacco packing machine according to one aspect of the present invention is used to automatically tie tobacco packs with hemp ropes, and is characterized by comprising:

[0009] A feeding mechanism, used for receiving cigarette packets to be knotted from an upstream device;

[0010] A transmission mechanism, used for transmitting the cigarette pack to be knotted to the knotting position;

[0011] A claw mechanism, having a plurality of claws, for winding the hemp rope around the cigarette pack; and

[0012] The knotting mechanism is provided with a plurality of knotters corresponding to the plurality of picking claws, and is used for rotating and knotting the hemp rope tied around the cigarette pack.

[0013] The automatic packaging machine also has a tensioning mechanism, which has multiple groups of tensioners corresponding to the number of the multiple groups of picking claws and the multiple groups of knotters, and is used to provide a constant tensioning force to the hemp rope during the knotting process of the cigarette pack.

[0014] According to the present invention, the constant tensioning force provided by the tensioning mechanism can keep the hemp rope in an appropriate tensioned state at all times, and can effectively avoid the phenomena of rope breaking and non-tripping.

[0015] Preferably, the weight of the object that can be pulled by the cross-sectional area of ​​a single hemp rope per unit area is set to m, the radius of the single hemp rope is set to r, the number of hemp rope strands is set to k, the maximum acceleration of the picking claw during the needle threading process is set to a, the reverse tensioning force from the tensioner is set to N1, the force required to pull the hemp rope in a natural state is set to N2, and the resistance of the cigarette pack to the hemp rope is set to N3, the reverse tensioning force N1 from the tensioner satisfies the following relationship

[0016] N1=π×r 2 ×m×k×g / a-N2-N3.

[0017] According to the present invention, appropriate tensioning force can be applied to the hemp rope during packaging operations under different production conditions, thereby more effectively avoiding rope breakage and non-tripping phenomena.

[0018] Preferably, when the bagging tool is a sack and the packaging tool is a φ6 and 4-strand hemp rope, the reverse tensioning force N1 from the tensioner satisfies the following relationship:

[0019] The value range of N1 is 14 Newtons to 17 Newtons.

[0020] More preferably, the value range of N1 is 15.6 N to 15.9 N.

[0021] More preferably, N1=15.8 Newton.

[0022] According to the present invention, the phenomenon of rope breaking and non-tripping can be effectively avoided by applying precise tensioning force to the hemp rope.

[0023] Preferably, the knotting mechanism comprises:

[0024] The eagle's beak is used to hold the hemp rope transmitted by the picking claws and twist the hemp rope to form a rope buckle by rotating;

[0025] A rope clamping plate, used for restraining the hemp rope held by the eagle's beak;

[0026] A rope cutting blade, used to cut the hemp rope after forming the rope loop; and

[0027] The rope pulling plate is used for peeling the formed rope buckle out of the eagle's beak.

[0028] According to the present invention, the knotting operation of the hemp rope can be performed efficiently.

[0029] Preferably, the multiple groups of picking claws, the multiple groups of knotters, and the multiple groups of tensioners are all formed into three groups.

[0030] According to the present invention, by providing three sets of picking claws, knotters and tensioners, when packaging agricultural products such as tobacco, which are longitudinally shaped and have large differences in physical properties at the head, middle and tail, tobacco packs can be formed more firmly.

[0031] Preferably, the plurality of tensioner groups are composed of magnetic powder clutches.

[0032] According to the present invention, the magnetic powder clutch can be used to form a prescribed constant tension force in real time and dynamically, thereby ensuring that the rope does not break or trip during the packaging process. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram showing the overall structure of the automatic tobacco packing machine of the present invention.

[0034] Figure 2 It is a structural schematic diagram showing a knotting mechanism.

[0035] Figure 3 It is a schematic diagram showing the structure of a knotter.

[0036] Figure 4 It is a curve showing the instantaneous acceleration at the needle tip of the picking claw during the knotting process. Description of the drawings:

[0038] 100 Tobacco Automatic Packing Machine

[0039] 1 Feeding mechanism

[0040] 2Transmission mechanism

[0041] 3. Pick-up claw mechanism

[0042] 31 Pick Claw

[0043] 32 Pick-up claw drive unit

[0044] 4 Knotting mechanism

[0045] 41 Knot tying machine

[0046] 411 Rope Clamp Plate

[0047] 412 Eagle Beak

[0048] 413 rope pull plate

[0049] 414 Rope Cutting Blade

[0050] 5. Tensioning mechanism

[0051] 51 Tensioner DETAILED DESCRIPTION

[0052] Various exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present invention and its application or use. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present invention thorough and complete and to fully convey the scope of the present invention to those skilled in the art. It should be noted that unless otherwise stated, the relative arrangement of the components and steps, numerical expressions, and numerical values, etc., described in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0053] The words “include” or “comprising” and the like used in the present invention mean that the elements before the words include the elements listed after the words, and do not exclude the possibility of also including other elements.

[0054] All terms (including technical terms or scientific terms) used in the present invention have the same meanings as those understood by ordinary technicians in the field to which the present invention belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined in this article.

[0055] Components not described in detail in this section, parameters such as specific models of components, relationships between components, and control circuits may be considered as technologies, methods, and equipment known to ordinary technicians in the relevant fields, but in appropriate circumstances, such technologies, methods, and equipment should be considered as part of the specification.

[0056] Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0057] Figure 1 1 is a schematic diagram showing the overall structure of the automatic tobacco packing machine 100 of the present invention. Figure 1As shown, the automatic tobacco baler 100 comprises: a feeding mechanism 1, a transmission mechanism 2, a picking claw mechanism 3, a knotting mechanism 4, and a tensioning mechanism 5. The feeding mechanism 1, the transmission mechanism 2, the picking claw mechanism 3, the knotting mechanism 4, and the tensioning mechanism 5 are installed on the frame of the automatic tobacco baler 100.

[0058] In the present invention, a continuous packaging method is adopted, that is, the bagging operation and the knotting operation are completed sequentially on the same production line, instead of loading the cigarette packs pre-loaded in the sacks from the middle of the frame 1. Thus, the efficiency of bagging and packaging can be improved.

[0059] A bagging mechanism is provided upstream of the feeding mechanism 1, but the illustration and description are omitted in the present invention. It can be considered that the tobacco packages entering the automatic tobacco packing machine 100 from the feeding mechanism 1 have been bagged and are filled with tobacco leaves in sacks.

[0060] The transmission mechanism 2 is a translation mechanism composed of a conveyor belt or the like. In addition, under the control of a control device (not shown), the speed and pause of the transmission mechanism 2 can be adjusted. For example, the transmission mechanism 2 works in a cycle of translation-pause (knotting operation)-translation. In the following description, the position where the tobacco automatic packing machine 100 ties the cigarette packs is referred to as the knotting position. That is, the transmission mechanism 2 pauses when each cigarette pack is transported to the knotting position to wait for the knotting operation of the cigarette pack.

[0061] The claw mechanism 3 is used to transport and thread the hemp rope. In the working state, the hemp rope is threaded onto the claw 31 of the claw mechanism 3. When the cigarette pack is transported to the specified position, that is, the knotting position, the claw mechanism 3 starts to rotate from the initial position, driving the hemp rope to go through an arc and bring the hemp rope to the knotting position, and then the knotting mechanism 4 completes the knotting operation. Subsequently, the hemp rope that has been knotted is cut off, and the claw mechanism 3 is reset to the initial position, waiting for the next cycle, that is, the knotting of the next cigarette pack.

[0062] The claw mechanism 3 includes a claw 31 and a claw driving unit 32. The claw driving unit 32 is a power component that drives the claw 31 to move, and can be composed of a motor or a hydraulic cylinder, a cylinder, etc. The claw 31 is usually configured as a large arc-shaped needle. Before the knotting operation, that is, before the cigarette pack is transported to the knotting position, the hemp rope is first passed through the wire hole at the head of the claw 31. A hemp rope groove is provided on the back of the claw 31. The hemp rope falls to the bottom of the knotting position of the cigarette pack as the claw mechanism 3 rotates. When the cigarette pack enters the knotting position, the claw 31 rises and cooperates with the knotting mechanism 4 to tie the hemp rope to the cigarette pack.

[0063] In the present invention, the claw mechanism 3 is provided with three groups of claws 31, corresponding to the knotting of the head, middle and tail of the cigarette pack, respectively. However, the number of claws 31 of the claw mechanism 3 is not limited thereto, and can be set to two or more groups as needed.

[0064] Figure 2 and Figure 3 4 is a diagram showing the structure of the knotting mechanism 4 in detail. Figure 3 As shown, the knotting mechanism 4 is provided with a number of knotters 41 corresponding to the number of the claws 31 of the claw mechanism 3. Each knotter 41 includes: a rope clamping plate 411, a hawk beak 412, a rope pulling plate 413, and a rope cutting blade 414. In addition, the knotting mechanism 4 is also equipped with a driving motor, etc., which is omitted from the figure.

[0065] After the cigarette pack is transported to the knotting position and the claw 31 of the claw mechanism 3 drives the hemp rope to the bottom of the cigarette pack, the claw 31 swings upward to tie the hemp rope to the cigarette pack. Then, the beak 412 of the knotter 41 rotates, and during the rotation, it opens and holds the hemp rope brought by the claw 31. In addition, the hemp rope is held by the beak 412 and located in the rope clamping plate 411. As the beak 412 continues to rotate, the hemp rope in the rope clamping plate 411 is twisted to form a rope buckle.

[0066] Next, after the rope buckle is formed by the beak 412, before the beak 412 is closed, the rope cutting blade 414 moves laterally to cut the hemp rope, and the rope pulling plate 413 simultaneously peels the rope buckle out of the beak 412. Thus, the whole knotting operation is completed.

[0067] However, as disclosed in the background technology section, existing knotting mechanisms usually use cotton ropes, nylon ropes, etc., which are smooth and easy to operate, while cigarette packs must be knotted using hemp ropes. Hemp ropes have the characteristics of high friction and low stretchability, and once the knot is tied, it is difficult to tighten it again.

[0068] Specifically, tobacco leaves are fluffy plant leaves that are compacted to a certain extent after being bagged. In addition, during the knotting process, the cigarette pack needs to be further compacted for knotting, and the hemp rope is in a tightly bound state during this process. After the knotting operation is completed, the rebound force of the cigarette pack will expand the cigarette pack and be bound by the hemp rope, so the hemp rope on the knotted cigarette pack is always in a tensioned state. In other words, the minimum tension of the hemp rope must at least be able to resist the rebound force of the cigarette pack.

[0069] However, in reality, it is not enough for the hemp rope to only resist the rebound force of the cigarette pack. This is because, when manually knotting, the worker usually compacts the cigarette pack with his body, such as using his legs or arms to compact the cigarette pack, and then wraps the hemp rope tightly around the cigarette pack to complete the knot manually. However, in automatic baling machines, the compaction of the cigarette pack before knotting is sometimes achieved by the tightening effect of the hemp rope, so the hemp rope needs to have a larger tension reserve. In addition, there are resistances in the transportation process of the hemp rope, such as the friction resistance of pulleys, etc., which also need to be taken into account in the tension reserve of the hemp rope.

[0070] The inventors of this application have found through many practices that due to the special properties of hemp rope, there are completely different issues when tying knots compared to nylon rope, cotton rope, etc. The following is a detailed description.

[0071] Theoretically, the thinner the hemp rope is, the more likely it is to be successfully knotted. However, due to the aforementioned rebound force of the cigarette pack after knotting and the requirement for a larger hemp rope tension reserve when tying a knot, the hemp rope cannot be set too thin, otherwise it is easy to break. According to practical experience and industry standards, φ6 (4-strand) hemp rope is usually used.

[0072] During the knotting process, if the tension of the hemp rope is too large (too tight), the rope is prone to breakage. However, if the tension of the hemp rope is too small (too loose), it is difficult for the beak 412 to tie a loose hemp rope, or the rope cutting blade 414 fails to find the rope buckle after the knot is successfully tied, or the rope pulling plate 413 fails to find the rope buckle and fails to peel the rope buckle out of the beak 412. Since the friction of the hemp rope is much greater than that of ropes made of other materials such as nylon rope or cotton rope, if the hemp rope cannot be pulled out before it is tied into a rope buckle, it cannot be pulled out once it becomes a rope buckle. The rope pulling plate 413 cannot peel the rope buckle off the beak 412, causing the rope buckle to continue to be held in the beak 412 without being detached.

[0073] This is the main difference between hemp rope and ropes made of other materials. In addition, as mentioned above, cigarette packs are usually bundled with more than three hemp ropes, and it is very difficult to synchronize the three sets of claws 31 and three sets of knotters 41 to complete the same action. The two main reasons for knotting failure when using hemp rope to tie cigarette packs are rope breakage caused by excessive tension of the hemp rope and failure to untie caused by insufficient tension of the hemp rope.

[0074] In order to verify this situation, the inventors of the present application verified it through experiments. Table 1 shows the success rate of knotting when the hemp rope is in a completely relaxed state and a completely fixed state. The hemp rope in a completely relaxed state and a completely fixed state respectively simulates the state where the tension of the hemp rope is too small, that is, too loose, and the hemp rope tension is too large, that is, too tight. Among them, the hemp rope is completely fixed means that during the knotting process, the other end of the hemp rope, that is, the end away from the eagle's beak, is completely fixed. In this case, the length of the hemp rope used for knotting this cigarette pack is fixed, and the length of the hemp rope cannot be supplemented or retracted. It can only rely on the tension reserve of the fixed length of the hemp rope itself to resist various forces.

[0075] Table 1

[0076]

[0077] It can be seen that when the hemp rope is completely relaxed, it is impossible to complete the knotting. The reason for the failure is that the aforementioned eagle beak 412 is difficult to tie the loose hemp rope, or the rope cutting blade 414 fails to find the rope buckle after the knot is successfully tied, or the rope pulling plate 413 fails to find the rope buckle and fails to peel the rope buckle out of the eagle beak 412. The above is collectively referred to as non-detachment.

[0078] Therefore, it is necessary to keep the hemp rope taut during the knotting process. However, when the hemp rope is completely fixed, that is, fully tensioned, the success rate cannot reach 100%. The inventors of this application speculate that when the elasticity of the cigarette pack is good, the cigarette pack can be tightened and the knot can be tied by relying on the tension reserve of the hemp rope. However, when the elasticity of the cigarette pack is poor, the hemp rope cannot resist the hard cigarette pack during the process of tightening the cigarette pack, and the tension of the hemp rope may reach a maximum at a certain moment, resulting in rope breakage.

[0079] Due to the different properties of different parts of tobacco leaves, or the different water content of new and old tobacco leaves, some tobacco bales will be more compact. In particular, the lower tobacco leaves contain more nodes and stems, and the tobacco bales piled together have poor elasticity.

[0080] In summary, when using hemp rope to tie cigarette packages, the hemp rope needs a certain degree of tension to avoid the phenomenon of not being able to be untied. However, the tension cannot be too large, otherwise the probability of rope breaking will increase. How to set the appropriate hemp rope tension is the key to the reliability of the automatic packaging machine for cigarette packages.

[0081] Therefore, the inventors of the present application found that when the hemp rope is completely fixed, although in most cases the rebound force of the cigarette pack and the resistance during the transportation of the hemp rope can be absorbed by the tension reserve of the hemp rope itself, when the elasticity of the cigarette pack is poor and exceeds the limit of the tension reserve of the hemp rope, the hemp rope still has the risk of breaking. It can be seen from the experiment in Table 1 that when the hemp rope is completely fixed, the failure rate is as high as 24%, which is unacceptable in actual production.

[0082] Based on the above research, the inventors of the present application found that the hemp rope cannot be set to be completely fixed, but should be given space for adjustment so that the hemp rope can always be kept in appropriate tension. That is, when the tension of the hemp rope is small, that is, when the hemp rope is loose, a part of the hemp rope is retracted at the end of the hemp rope away from the beak 412, that is, the release end of the rope roll, so that the hemp rope continues to be tensioned. When the tension of the hemp rope is large, that is, when the hemp rope is too tight, a part of the hemp rope is released from the end of the hemp rope away from the beak 412, that is, the release end of the rope roll, so as to relieve the tension of the hemp rope.

[0083] That is, the length of the hemp rope used for tying knots is dynamically adjustable, so that the tension of the hemp rope can always be maintained at an appropriate size.

[0084] In order to achieve this purpose, the inventors of the present application set a tensioning mechanism 5 in the automatic knotting machine. The tensioning mechanism 5 has a number of tensioners 51 corresponding to the number of claws 31 of the claw mechanism 3 and the number of knotters 41 of the knotting mechanism 4. Specifically, the tensioning mechanism 5 is composed of a magnetic powder clutch, for example, and can release or retract a part of the hemp rope in real time and dynamically according to the current tension of the hemp rope, so as to always keep the tension of the hemp rope at an appropriate size. Of course, those skilled in the art can understand that the tensioning mechanism 5 of the present invention is not limited to being composed of a magnetic powder clutch, and can also be realized by other structures under the condition that a fixed tension of the hemp rope can be achieved.

[0085] Next, the inventors of the present application studied the setting of the tensioning force of each tensioner 51 of the tensioning mechanism 5. As mentioned above, the tensioning force of the tensioner 51 should not be too large or too small. If the tensioning force of the tensioner 51 is too small, the hemp rope will be too loose and will not be released. If the tensioning force of the tensioner 51 is too large, there will be a risk of rope breaking.

[0086] First, the theoretical basis of hemp rope tension is studied. Assuming the tension of the hemp rope is N, during the knotting process, the tension N of the hemp rope comes from multiple factors.

[0087] First, when the tension mechanism 5 is provided, the reverse tension force from the magnetic powder clutch is set to N1.

[0088] The force required to pull the hemp rope in the natural state is set to N2. Specifically, when the hemp rope is knotted, it needs to pass through several pulleys, and then the claw 31 drives the needle to be threaded and knotted, so there will be a certain natural resistance.

[0089] The cigarette pack resistance is set to N3. Specifically, when the knotter 41 is tying a knot, the knotter 41 drives the hemp rope transmitted by the picking claw 31 to rotate, which will cause the hemp rope to be squeezed into the cigarette pack to a certain depth. The hemp rope needs to resist the rebound force of the cigarette pack, thereby bearing the resistance of the cigarette pack, that is, the friction of the cigarette pack.

[0090] Therefore, the tension on the hemp rope is N = N1 + N2 + N3, which is equivalent to the tension required for the hemp rope to lift an object with a weight of M.

[0091] Mg=N1+N2+N3 (1)

[0092] Where g is the acceleration due to gravity.

[0093] In addition, the maximum acceleration of the pick claw 31 during the knotting and threading process is a. Therefore, during the knotting process, the minimum tension N that the hemp rope can withstand is

[0094] N=M×a=(N1+N2+N3) / g×a; (2)

[0095] Assume that the weight of the object that can be pulled by a single-strand hemp rope per unit area is m, the radius of the single-strand hemp rope is r, and the number of strands of the hemp rope is k. Therefore, the tension n that the hemp rope can withstand is

[0096] n=π×r 2 ×m×k (3)

[0097] The tension N is equivalent to the tension n, so the relationship between the hemp rope model (radius, number of strands, etc. of a single hemp rope) and the reverse tension of the magnetic powder clutch is:

[0098] (N1+N2+N3) / g×a=π×r 2 ×m×k (4)

[0099] By transforming formula 4, we can get:

[0100] N1=π×r 2 ×m×k×g / a-N2-N3

[0101] In production practice, in order to cooperate with the knotting mechanism 4, the instantaneous speed of the needle tip of the claw 31 when threading the needle needs to reach 0.7m / s. In order to overcome the self-weight of the claw 31 and reach the needle threading speed, a 1.5KW motor is used, with an output torque of 22.6~27.1NM, a gear speed ratio of 21:40≈1:2, a 4-link mechanism input end torque of 45.2~54.2NM, and a speed of 1500 / 2 / 30=25rpm. After actual measurement, the needle tip line acceleration curve of the claw 31 is as follows Figure 4 shown.

[0102] from Figure 4 It can be seen that the maximum linear acceleration of the needle of the pick claw 31 is 2.625 m / s 2 , so a=2.625 m / s 2 . The weight of an object that can be pulled by each square centimeter of cross-sectional area of ​​a standard hemp rope is m = 150 kg. The hemp rope is φ6 (4-strand) hemp rope, and the radius of each strand is 0.075 cm. Through actual measurement, it takes 3.6 Newtons of force to pull the hemp rope, that is, N2 = 3.6 Newtons. The rotation of the knotter 41 during knotting pulls about 50 mm of hemp rope. The upper surface of the cigarette pack is not subjected to force, while the remaining three surfaces are subjected to force and will be squeezed into the cigarette pack by the hemp rope. After actual measurement, in order to ensure a good packaging effect, the depth of the hemp rope squeezed into the cigarette pack is approximately 16.7 mm. Using a cigarette pack with relatively large elasticity to test the hemp rope to squeeze 16.7 mm into the sack, it takes about 20.9 Newtons of force, so N3 = 20.9 Newtons, and formula (4) can be obtained

[0103] N1=3.14×0.075 2 ×150×4×9.8 / 2.625-3.6-20.9

[0104] It can be calculated that N1=15.064 N. It can be seen that under the aforementioned parameter conditions, it can be obtained that the reasonable tensioning force of the tensioner 51 should be set to about 15 N. It should be noted that the reasonable tensioning force of the tensioner 51 is calculated through the aforementioned parameter conditions and measured data. When targeting different production conditions, different production materials, or different automatic balers, N2 and N2 can also be obtained through actual measurement and calculation, and parameters such as r, m, and k can be obtained through query.

[0105] However, there are differences between the theoretical basis research and the actual situation. However, through the theoretical basis research, the experimental range of the tensioning force N1 of the tensioner 51 is greatly narrowed. In the following, within the range of N1=15 Newton, the inventors of the present application conducted multiple experiments to explore the optimal tensioning force value of the tensioner 51.

[0106] Table 2 shows the results of experiments in which the tensioning force of the tensioner 51 was within the range of 12 N to 18 N. This experiment corresponds to the first stage experiment.

[0107] Table 2

[0108]

[0109]

[0110] Through the first phase of the experiment, it can be seen that as the tension of the tensioner 51 increases, the knotting success rate gradually increases, reaching 100% at 16 N. If the reverse force continues to increase on the basis of 16 N, the rope will begin to break. Therefore, it is known that the optimal tension of the tensioner 51 is around 16 N, and more accurate data is obtained.

[0111] Due to the limited number of tests in the first phase of the experiment, the tensioning force of 16 N still does not reach the ideal accuracy and requires further actual production verification. The inventors of the present application set the tensioning force of the tensioner 51 to 16 N and conducted a large number of actual production verifications to verify the optimal tensioning force of the tensioner 51 through a large amount of actual production data.

[0112] In actual production, under a tension of 16 N, 10 knotting failures did occur in 1,190 knotting attempts. Actual production can provide a large amount of verification data, so by fine-tuning the reverse force in actual production, fine-tuning once for every 10 knotting failures can further improve the knotting success rate.

[0113] Table 3 shows the results of a large number of actual production verifications based on a method of fine-tuning the tensioning force of the tensioner 51 downward by 0.1 Newton after accumulating 10 knotting failures.

[0114] Table 3

[0115] Tension Number of experiments Number of successes No tripping Rope Break Success rate 16 cattle 1190 1180 2 8 99.16％ 15.9N 2792 2782 4 6 99.64％ 15.8N 6355 6345 8 2 99.84％ 15.7N 3811 3801 10 0 99.74％ 15.6N 1950 1940 10 0 99.49％

[0116] As can be seen from Table 3, under a tension of 16 N, most failures are caused by rope breakage. Since a large tension is more likely to cause rope breakage, this shows that a tension of 16 N is still slightly too large. Therefore, in the subsequent experimental process, we first tried to reduce the tension, and the experimental results also proved that the tension of 16 N was too large. When it was adjusted to 15.8 N, the knotting success rate increased significantly, reaching 99.84%. When the tension was further reduced to 15.6 N, the knotting success rate would be significantly reduced, which shows that the phenomenon of non-tripping caused by the relaxation of the hemp rope began to increase, so there was no need to continue to reduce the tension for experiments.

[0117] The following is a summary of the research and experimental process.

[0118] Firstly, by adding the tensioner 51, the problem that the hemp rope cannot be automatically knotted when the hemp rope is completely fixed or completely relaxed is solved.

[0119] Secondly, the theoretical optimal tensioning force of the tensioner 51 can be obtained by formula 4. It can be seen from the experimental results in Table 2 that the theoretical optimal tensioning force of the tensioner 51 obtained by formula 4 can obtain a knotting success rate of about 98%, so it is feasible to guide the setting of the tensioner 51 by formula 4.

[0120] Furthermore, when a higher knotting success rate is required, the inventors have conducted a large number of experiments and have accurately adjusted the tensioning force of the tensioner 51 to 15.8 Newtons, which can achieve a knotting success rate very close to 100%.

[0121] Through the keen exploration of the inventors of this application, the problems of easy breaking and easy unfastening of hemp ropes have been successfully solved, and the automatic knotting of cigarette packages using hemp ropes has been fully automated.

[0122] The above describes the specific implementation methods of the present invention, but it should be understood that the specific embodiments described above are only used to explain the present invention, and the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, shall be included in the protection scope of the present invention.

Claims

1. An automatic tobacco packing machine, used for automatically tying tobacco packs with hemp ropes, characterized in that: have: A feeding mechanism, used for receiving cigarette packets to be knotted from an upstream device; A transmission mechanism, used for transmitting the cigarette pack to be knotted to the knotting position; A claw mechanism, having a plurality of claws, for winding the hemp rope around the cigarette pack; and The knotting mechanism is provided with a plurality of knotters corresponding to the plurality of picking claws, and is used for rotating and knotting the hemp rope tied around the cigarette pack. The automatic tobacco packing machine also has a tensioning mechanism, which has multiple groups of tensioners corresponding to the number of the multiple groups of picking claws and the multiple groups of knotters, and is used to provide a constant tensioning force to the hemp rope during the knotting process of the tobacco pack.

2. The automatic tobacco packing machine according to claim 1, characterized in that: When the weight of an object that can be pulled by a single-strand hemp rope per unit area is set to m, the radius of the single-strand hemp rope is set to r, the number of strands of the hemp rope is set to k, the maximum acceleration of the picking claw during the needle threading process is set to a, the reverse tensioning force from the tensioner is set to N1, the force required to pull the hemp rope in a natural state is set to N2, and the resistance of the cigarette pack to the hemp rope is set to N3, the reverse tensioning force N1 from the tensioner satisfies the following relationship <h2 style=";text-align:left;direction:ltr">N1 = π×r<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> ×m×k×g / a-N2-N3。 3. The automatic tobacco packing machine according to claim 2, characterized in that: When the bagging tool is a sack and the packaging tool is a φ6 and 4-strand hemp rope, the reverse tensioning force N1 from the tensioner satisfies the following relationship: The value range of N1 is 14 Newtons to 17 Newtons.

4. The automatic tobacco packing machine according to claim 3, characterized in that: The value range of N1 is 15.6N to 15.9N.

5. The automatic tobacco packing machine according to claim 4, characterized in that: N1=15.8N.

6. The automatic tobacco packing machine according to any one of claims 1 to 5, characterized in that: The knotting mechanism comprises: The eagle's beak is used to hold the hemp rope transmitted by the picking claws and twist the hemp rope to form a rope buckle by rotating; A rope clamping plate, used for restraining the hemp rope held by the eagle's beak; Rope cutting blade, used to cut the hemp rope after forming the rope buckle; as well as The rope pulling plate is used for peeling the formed rope buckle out of the eagle's beak.

7. The automatic tobacco packing machine according to any one of claims 1 to 5, characterized in that: The multiple groups of picking claws, the multiple groups of knotters, and the multiple groups of tensioners are all formed into three groups.

8. The automatic tobacco packing machine according to any one of claims 1 to 5, characterized in that: The multiple sets of tensioners are composed of magnetic powder clutches.

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